The invention relates to electric lamps and particularly to replaceable automotive lamps. More particularly the invention is concerned with replaceable automotive lamps formed with LED chips.
Most automotive signal lamps currently use incandescent filaments, gas discharges or light emitting diodes (LEDs) as light sources. Typically the light is reflected by a simple mirrored surface through a cover lens to the illuminated field. The package depths of these assembles are typically about 3 to 6 inches, and they have a projection surface area of 25 square inches or more. To manufacture vehicle lamp thinner than this requires a highly complex reflector and lens system whose components are expensive and susceptible to functional and cosmetic defects.
As initially manufactured, an LED chip is cut from a semiconductor wafer. This initial piece is called a die. LED chips are commonly mounted in a supporting package, which is then mounted as a light source. It is this plastic package enclosing the LED chip what is commonly seen and referred by users as an LED. A portion of the generated light is necessarily lost to the package and the associated reflector structures. Minimizing the package shadow, and maximizing the reflectivity in the package cavity are necessary to achieve a good package design. None the less, even a good package cavity absorbs a significant amount of the generated light. The degree of absorption can be significant in automotive lighting where electrical efficiency, minimal size, and minimal weight are important objectives. The typical frame and reflector structure are usually so close to the LED chip that they trap the heat that then reduces the life of the LED chip. LEDs provide small, relatively efficient light sources, but to generate sufficient total light, many LEDs must be ganged together. As a result, when the LED""s are used in an optical system they commonly appear as an unaesthetic cluster of bright dots. There is then a need for a different mounting scheme to more effectively use the generated light from an LED. There is also a need to reduce the heat generated by the LEDs to enhance their life. There is a further need for a different mounting and optical system to create a more esthetic light pattern from the light generated by the LEDs.
A vehicle light source may be formed as a replaceable lamp capsule having a support defining a lamp axis extending in a forward direction towards a field to be illuminated, the support directly supports one or more LED chips, each LED chip having a predominate LED axis of light emission, the majority of the LED chips being oriented so their respective LED axis""s form an angle with the forward lamp axis direction of ninety or more degrees. The emitted light may then be directed by a reflector in the forward direction.